So, you want Ming to essentially be an airbending master at thirteen. No. There are twenty-six tiers to airbending and some monks don't even get close. Aang, the Avatar, was the youngest at 12, and he only got 25 tiers as well as made a new technique. The character feels like you just wanted to "Master airbending, then move on to the plot" and I'm not going to allow that. There's not a strong enough sense of culture or identity, and there's no way he mastered advanced-level techniques at such a young age.